(Iowa Capital Dispatch) – Warm soil temperatures and favorable weather have allowed farmers across Iowa to start planting corn and soybeans this week, according to several field agronomists. Wednesday was the earliest planting date for corn to be eligible for federal crop insurance replanting payments, which cover farmers if their young crops are damaged and need to be replaced. The earliest planting date for soybeans was also Wednesday for the southern three tiers of Iowa counties, and it’s April 15 for the rest of the state.

Most of the state’s topsoil has a temperature of at least 50 degrees, according to Iowa State University data. That temperature is a key threshold for seed germination. Soil temps are predicted to rise into the 60s in the coming days before retreating into the 40s by the end of next week. Air temperatures are expected to peak in the 80s in most of Iowa this weekend, according to the National Weather Service. Heavy rainfall in wide areas of the state in March helped alleviate drought conditions that have persisted for more than three years. Still, available soil moisture is far behind what it has been in recent years.

About 51% of the state’s topsoil and 36% of its subsoil have adequate or surplus moisture, according to a U.S. Department of Agriculture report on Monday. At this time last year, those figures were 78% and 66%. The depleted subsoil is most worrisome for the field agronomists. About two-thirds of the state is suffering from some measure of drought, according to a Thursday report by the U.S. Drought Monitor. That affected area has declined for weeks and was aided again last week by heavy rainfall in southeast Iowa, which delayed planting in that area.

Those rains have alleviated some of the concerns about available water for livestock along the state’s southern border.